Autonomous Planning and Experiments of Space Robot Based on Hand-eye Measurement

The robotic on-orbital service, whose key is the capturing technology, becomes research hot in recent years. In this paper, the authors propose an autonomous path planning method for target capturing. The term autonomous means that "to predict the target motion autonomously", "to avoid the dynamic singularities autonomously" and "to adjust the manipulator motion without excess disturbance on the base autonomously". First, the target feature is extracted based on the measured information via the hand-eye camera, and the target velocities are estimated using extended Kalman filtering technology. Then, a practical approach is presented to plan the manipulator motion and avoid the dynamic singularities, which transforms them into real-time kinematic singularities avoiding problem. Third, the manipulator motion is adjusted according to the predicted disturbance on the base, to limit the base angular velocity. At last, a ground experiment system is set up based on the concept of dynamic emulation and kinematic equivalence. With the experiment system, the autonomous capturing of space target is examined. The experiment results validate the proposed algorithm.